Solid carbonaceous materials, such as coal, have long been employed as a fuel source whether it be by simple combustion or conversion into a gaseous or liquid fuel. Certain coals when suitably processed into coke also provide an essential raw material in iron making.
All coals contain mineral particulates to some degree. Excessive levels of such mineral particulates are undesirable as they interfere with the combustion of the coal and the formation of coke. The particulates also lead to undesirable increases in ash levels during processing and combustion. Prior to utilisation, most coals have traditionally undergone a washing treatment. During such a treatment, finely divided coal or coal fines of varying sizes are washed into the waste water together with the mineral particulates and other gangue materials. These coal tailings are typically held in settling ponds on the mine site. In addition to representing a loss of coal, the disposal of the waste water can represent an environmental hazard.
It would be desirable to provide a new means of processing coal slurries that provided desirable beneficiation of coal fines and the production of a coal product that could be readily handled and, if desired, further processed as required. It would also be desirable but not essential that the new process in providing this improved beneficiation had a cost of production similar to or not significantly higher than presently used processes.